Optical transceiver modules are used to transmit and receive optical signals over optical communications networks. These modules typically use lasers to generate optical signals that are then transmitted over optical fibers and photodiodes to receive optical signals, which are then demodulated to recover the data. The modules typically include a transceiver module controller that controls the operations of the transceiver module. This controller is typically in communication with a remote host computer via a wired link of some sort to allow the transceiver module to be remotely monitored. The host computer typically monitors the transceiver operations and may send maintenance signals to the transceiver module for various purposes, such as to control the laser drivers to ensure that the optical signals produced by the lasers have the proper output intensity levels.
FIG. 1 illustrates a block diagram of a transceiver module 2 currently used in optical communications. The transceiver module 2 includes a transmitter portion and a receiver portion. The transmitter and receiver portions are controlled by a transceiver module controller 14. The transmitter portion includes a laser driver 1, a laser 12, a monitor photodiode 13, and a transceiver module controller 14. The laser 12 is typically a laser diode. The laser driver 11 receives an input data signal, Data In, and generates electrical signals that are used to directly modulate the laser diode 12 to cause it to output optical signals that have power levels corresponding to logic 1s and logic 0s. An optics system (not shown) of the transceiver module 2 focuses the coherent light beam produced by the laser diode 12 into the end of a transmit optical fiber 15 held within a connector (not shown) that mates with the transceiver module 2.
The monitor photodiode 13 monitors the output power level of the laser diode 12 and produces an electrical analog feedback signal that is delivered to the transceiver module controller 14. The controller 14 processes the feedback signal to determine the average output power level of the laser diode 12. The controller 14 outputs control signals via line 17 to the laser driver 11 to cause it to adjust the bias current signal it outputs to the laser diode 12 such that the average output power level of the laser diode 12 is maintained at a relatively constant level.
The receiver portion of the transceiver module 2 includes a receive photodiode 21 that receives an incoming optical signal output from the end of a receive optical fiber 22. An optics system (not shown) of the receiver portion focuses the light output from the end of the receive optical fiber 22 onto the receive photodiode 21. The receive photodiode 21 converts the incoming optical signal into an electrical signal, which is then amplified by an amplifier 25. The amplified signal corresponds to the Data Out signal for the transceiver module. Information relating to the electrical signal received by the amplifier 25 from the photodiode 21 is typically also communicated to the transceiver module controller 14.
The transceiver module controller 14 may be accessible by and communicate with a remote host computer (not shown), as described above, to enable the remote host computer to monitor and/or control the operations of the transceiver module 2. The connection between the transceiver module 2 and the host computer is typically a wired connection for providing a link to a wired network, such as the Internet. The information that is typically communicated between the transceiver module and the host computer is low-bandwidth maintenance data.
For a variety of reasons, it would be desirable to provide communications links other than, or in addition to, the types of wired links that are currently used as communications links between optical transceiver modules and remote host computers. For example, one reason for this is that if the wired communications link fails for some reason, it would be desirable to have an alternate communications link between the transceiver module controller and the host computer. Another example of a reason to have an alternative communication link is to provide an alternative path for the high-speed data that is typically transmitted and received today by optical transceiver modules.
Accordingly, a need exists for an optical transceiver module that is capable of communicating with a remote host computer or other device over a communication link other than the wired link that is typically provided in transceiver modules today.